This invention relates to the method by which the interior of an underground fuel tank may be lined to enable leak monitoring thereof and to prevent ground water from entering the tank and for preventing fuel from passing into the ground.
The problem of leaking underground fuel storage tanks has become immense and one of national concern. If a crack develops in the metal storage tank, ground water can enter the tank and mix with the fuel. A more serious problem is that if a crack or leak develops in the fuel storage tank, the fuel from the tank will pass outwardly therefrom and will contaminate the ground around the tank as well as the ground water near the tank.
One solution to the problem is disclosed in U.S. Pat. No. 4,796,676 wherein a system is disclosed which includes a flexible liner positioned within the interior of the tank and including a negative pressure or vacuum system for drawing the flexible liner into close association with the interior wall surface of the metal storage tank. The requirement that a vacuum always be present to maintain the liner against the interior of the storage tank requires extensive apparatus and maintenance in itself. Further, it is not easy to install such a negative pressure or vacuum system on tanks that are already positioned within the ground.
Therefore, it is a principal object of the invention to provide an improved method for preventing leakage from an underground fuel storage tank.
A further object of the invention is to provide a method of preventing leakage from an underground fuel storage tank wherein a flexible thermoplastic liner is maintained in position adjacent the interior wall surfaces of the metal storage tank by means of a polyester resin material.
A further object of the invention is to provide a method of preventing leakage from an underground fuel storage tank and including a leak-monitoring means associated therewith.
Still another object of the invention is to provide an underground fuel storage tank including means associated therewith for preventing leakage therefrom and for monitoring leaks.
Still another object of the invention is to provide a method by which an underground fuel storage tank may be retrofitted so as to prevent leakage therefrom.
These and other objects of the present invention will be apparent to those skilled in the art.